For years Brett Gardner has rated as the best defender in baseball. He's accumulated tons of runs saved according to UZR, shagging flies and diving for balls ... in left field. Gardner's defense was difficult to assess fully because he was playing out of his natural position. In addition, in a game that now uses relative measures to value defense, Gardner was being compared to inferior defenders. Left fielders are not center fielders. Typically they are among the worst defensive players on the field, while center fielders are among the best. This favorable comparison, it was often suggested, juiced Gardner's UZR results.
Now that Curtis Granderson is injured, Brett has been called upon to play center field. As a result, we can get our first glance at how his defense ranks compared to other center fielders. The answer is a bit disappointing. In center Gardner rates as good, but not great. So far this season his UZR is +5.3. That puts him in elite company, but it is far from the best rank in the game. It seems the assessment that Gardner wasn't as good a defender in center had some truth to it after all.

As disappointing as that revelation may be, it is worth mentioning that Gardner remains one of the best all-around players on the Yankees. In fact, according to Fangraphs, Gardner is the best player on the Yankees. His fWAR of 2.8 so far this season puts him in front of Robinson Cano and his 2.2 fWAR. Gardner does a little bit of everything well. He defends well. He runs the bases well. This year he's hitting well, with a wOBA of .348. As disappointing as it is to encounter evidence that Gardner may not be the stud defender we thought he was, being the best player on the Yankees isn't bad either.